The oil giant began the review earlier this year, drawing interest from a number of global PR networks.

The multimillon dollar brief aimed to improve PR quality and generate greater communications consistency, focusing in particular on a number of key Shell units, including corporate communications and global commercial, covering Shell's B2B sales to such industries as aviation and marine.

The review was effectively global in nature, spanning multiple international markets across EMEA, North America, Asia-Pacific and Latin America.

After a competitive tender, Shell has, for the most part, opted to continue working with agencies that were already in place. Edelman remains the company's key retail partner, while Burson-Marsteller — the company's other primary agency — is expected to form part of WPP's 'Team Shell' arrangement.

A Shell spokesman declined to provide further details regarding the breakdown of PR duties. WPP initially formed Team Shell to service the company's media business in 2005.